Mean Gene

Sark - Since we know that inflation has hit since I priced the Accuvolts 2 years ago, I E-beamed them & received the following response: Current ( HA-HA!! ) prices are - FR1500/$549; FR750/$397; & FR375/$297. Paul Rodgers ( the Jacobs tech who replied ) said he could do the following pricing if we got a group buy of at least 6 units total & THEY'LL pay the S&H via normal UPS ground service - FR1500/$413; FR750/$298; & FR375/$223. These discounts reflect a 25% markdown per unit so there's some food for though!

sarkastro

i emailed em as well though the rep that responded said I would probably need two of the 750 models for whatever reason. My shop's telling me I don't really need one at all, but it seems like a good idea to me. I've got a cap in right now, but from what I've read about them (correct me if the info is off), they only hold enough power for a brief period and have to recharge. That to me says if two subsequent bass notes need that extra juice, it may or may not be there for it. Is my thinking correct on that?

P.S My 7977 came in, and it's going in Saturday. I can't wait!

Mean Gene

Sark - Sure, if ya have enough heavy bass notes hit in a row then the cap may not have a chance to recharge ( pretty instantaneous for general listening ). That's why it's a good addition to a system - your 12V battery can't recharge quickly enough either so the cap will hold that 1 farad charge in reserve for when the amp demands it ( after several bass notes in sequence ). That's also why I can't see using an Accuvolt on your mids & highs as the amps driving those components RARELY pull the kind of amperage draw that a subwoofer/amp combo does. If U use the Accuvolt ( & most of my friends who do installs also feel they're overkill as well as your shop but hey, it's YOUR car! ), I'd just use a single FR750 on your bass amp ( bd500 ). Is your existing cap a 1 farad? If so, that should take care of your VDC power needs. About a higher voltage alternator - IMO & IME, they can add noise ( whine ) to your system & for a basic system like your I just can't see the need. My system pulls over 200 amps ( using manufacturers ratings only & not actually metered - YET! ) & I've never dimmed the lights. Start small & we'll add on as needed! :eek:
BTW - That 7977 has a 5 volt preamp voltage so it should clean up your minimal system noise that the 2 volt Pioneer couldn't.

Percy

Gene,

How about this for an idea? (Kicking in technician/electronics mode...) If they were to make a 1 farad cap using multiple 220 microfarad caps in a parallel configuration? The main reason why big caps and batteries can't recharge as fast is due to internal resistance and the size of the plates used in the capacitors. If they were to make a small "bank" of capacitors equaling one large one then you would have an advantage of faster recharging due to the smaller individual caps. This would be a marketable solution.

Or...if Krell can sell their patent of Sustained Plateau Bias and use it in car audio. That is, the power supply isn't passive, it's completely active to account for large and quick bass transients. There's a microprocessor that senses when the amp is going to need more of a power draw . I've NEVER seen a Krell amp run out of steam, especially when huge multiple bass notes hit. A definite technology that SQ guys (at home) have that can be used in the SPL realm.

Percy

Mean Gene

P - Seems so simple, doesn't it? Haven't torn down one of those 15 farad CAP's by AlumiPro - maybe they use the same technology. I totally agree that a bank of smaller caps would handle multiple bass notes better than one large capacitor, especially from the recharging standpoint. Have U modded your Krell in the GS like that yet even though it might be overkill for your system designs?

Percy

Gene,

For that level of sophistication I would need to look inside one of the Krell FPB 600's. At last cost those well selling around 10 to 12 grand and Krell doesn't sell any of it's technical schematics or parts due to patent reasons (which is probably why there are no Krell authorized repair centers other than Krell itself). Took me a long time just to get the analog board/preamp board from Krell that I have now! And that was from Dan D'Agostino himself!

It would be pretty neat to incorporate this technology in the car audio realm. Those with SPL rigs can really appreciate this!

About the only other manufacturer that I know that uses something similar is from Mark Levinson. They had to reverse engineer a Krell amp and not infringe on any of the patents. I do believe this is used in their No. 33 monoblocks. Also an expensive piece!

Percy
Using Krell as preamp/analog combo only...